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Old 14-05-2015, 07:18 AM
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sjastro
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Quote:
Originally Posted by N1 View Post
Steven, how do you know that a spherical surface is finite when your entire existence is inside same surface?
Mirko,

We live on a (near) spherical surface. We can travel around along a great arc on the Earth's surface and end up in the same spot we departed. Clearly this is not possible if the surface is infinite.

Cosmologists have used a similar principle to test if the Universe in finite and spherical. A photon emitted could traverse a spherical Universe and end up near the same spot of emission.
Since the anisotropic regions of the cosmic radiation background can now be well resolved, double images in the background would indicate this phenomena.

Regards

Steven